1. Field of the Invention
The present invention relates to an apparatus for non-contacting feeding of a high frequency power developed by a self-excited oscillation circuit, and more particularly, to a non-contacting high frequency power feeding apparatus for use as a non-contacting charger for electric cars, cardiac pace makers, induction-heating cookers, etc.
2. Description of the Prior Art
Heretofore, various ideas have been proposed to reduce the air pollution with the exhaust gases from the cars driven by any petroleum fuel engines and the annoying noise from such engines. One of the ideas is to use in the car an electric motor supplied with a power from rechargeable batteries. In various advanced countries, the research and development of such electric cars are under promotion.
The requirements for a wider prevailing of such electric cars are a more compact design, lighter weight, longer life, higher output of the batteries, etc. as well as a more compact design, lighter weight, shorter charging time, etc. of the charger. At present, electric cars for specific applications are limitedly used in defined areas.
The ordinary battery charger consists of a transformer provided for transformation of a commercial frequency power, and a rectifier circuit, control circuit, etc. provided at the secondary side of the transformer. Among the charger components, the transformer being larger and heavier than the rest cannot be reduced so much in size and weight because it is to operate with a commercial frequency. Therefore, the charger size and weight are still large and the conversion efficiency is low.
In these circumstances, it has been needed to develop a battery charger being compact and lightweight and high conversion efficiency, easy to operate and operable highly economically.
Small, long-life batteries have been developed and used in practice for the cardiac pace makers. However, since they are a primary cell, it has to be replaced with a fresh one before its life comes to end. For this battery replacement, the patient carrying the battery buried in the body must be subject to a surgery in a hospital. The patient cannot avoid such pains and also has many restrictions in the daily life.